1. Field of the Invention
The invention relates generally to a connector system for an exhaust extraction system, and more particularly to a connector system for attaching a conduit to the exhaust pipe of an internal combustion engine.
2. Description of the Related Art
Numerous situations exist in which an internal combustion engine needs to be operated inside a structure, such as a garage. For example, car engines may need to be tuned and tested inside a repair shop. Emergency vehicles, such as ambulances and fire engines, are generally stored inside an emergency medical services (EMS) station or a fire station. Exhaust fumes enter the EMS station or fire station as the vehicle enters or leaves the station. In addition, there may be a need to run the engine inside the station for extended periods of time, for example when running a pump test on a fire engine.
Internal combustion engine exhaust fumes, in particular diesel fumes, have been identified as serious health hazards. There is a need for systems that remove air pollutants from the air inside buildings. The preferred method comprises capturing the fumes at the exhaust pipe of the internal combustion engine, and guiding the fumes to the outside of the building. To this end systems have been developed comprising a flexible hose provided with a nozzle for connecting the hose to the tailpipe of a vehicle. The hose is connected to a vent opening, for example in the roof of the building. In most cases the system comprises a fan for extracting exhaust fumes.
The operation of such systems generally involves the following steps. As the vehicle returns to the station, it is stopped just outside the station so that the tailpipe of the vehicle is within reach of the hose nozzle. A crew member attaches the nozzle to the tail pipe, upon which the vehicle enters the station. Many exhaust systems are provided with sensors to ensure automatic operation when the hose is connected to the tailpipe of a running engine. Typically the exhaust hose is kept connected to the tailpipe of the vehicle while the vehicle is in the station.
Upon leaving the station the nozzle needs to be disconnected from the tailpipe. Disconnection desirable occurs at a predetermined location, for example at the door opening of the station.
The nozzle connecting the hose to the tailpipe desirably meets a number of requirements. Alignment of the nozzle with the tailpipe should be quick and easy. The nozzle should make a robust and secure connection to the tailpipe. Release of the nozzle desirably occurs automatically as the vehicle leaves the station and the end of the tailpipe passes a predetermined point.
U.S. Pat. No. 5,927,759 to Hyslop discloses a connection assembly for an exhaust connection system. The assembly comprises three primary components. The first component is an annular sleeve designed to be attached to the tailpipe of a vehicle. The second component is a nozzle locator ring, which slides onto the annular sleeve. The third component is an exhaust nozzle assembly designed to slide onto, and fit up against, the nozzle locator ring. The exhaust nozzle assembly contains two magnet packs, which contact the outer surface of the annular sleeve when the exhaust nozzle assembly is connected.
The connection assembly disclosed in this reference is relatively complex. The need to slide the nozzle assembly over the ring makes alignment awkward and difficult. The assembly does not reliably disconnect automatically if the exhaust pipe of the vehicle is not parallel to the longitudinal axis of the vehicle.
U.S. Pat. No. 5,096,230 to Pausch et al. discloses a quick-release adapter for connecting the inlet of an exhaust removal hose to the outlet of the tailpipe of a vehicle. The adapter includes three disk-like permanent magnets, and three receptacle-shaped magnetic connectors secured to the outlet of the tailpipe. Alignment of the adapter to the outlet of the tailpipe is difficult and cumbersome, as it requires the simultaneous alignment of all three magnets with their respective connectors.
Thus, there is a particular need for a connector system facilitating the alignment of the nozzle with the outlet of the vehicle tailpipe. There is a further need for a system that reliably and automatically disconnects as the vehicle leaves the station, while providing a secure seal when the engine is in use.